Blender attachment points for Trainz asset
If you want to get a mesh from Trainz you will need to figure out what format the game uses and if necessary convert it to a format that blender supports importing (OBJ or FBX are good ones). You may then need to set up textures again in Blender.

However attachment points are something specific to the game, and not something blender understands. To create attachment points you need to add an empty at the right location and prefix its name with "a." (e.g. a.attachment_1). It looks like the game will infer that it is an attachment point based on this convention.
https://en.wikibooks.org/wiki/Trainz/Tutorial_for_Blender#Attachment_Points
http://online.ts2009.com/mediaWiki/index.php/Attachment_point
http://online.ts2009.com/mediaWiki/index.php/HowTo/Export_from_Blender_using_FBX